Cassandra: When I first heard that she was going to be a party member I rolled my eyes so hard that it was practically audible. But she really grew on me after a while, to the point that I never took her out of my party.
Varric: I liked him in 2 but because he was a returning character I never felt the need to bring him anywhere. Kinda wish he was an adviser instead.
Solas: He was fine but kinda boring. To be fair, I didn't spend much time talking to him so he might have gotten way more interesting if I had. Also his reveal at the end of the game is making me heavily consider rolling with him more on my second play through.
Vivienne: I have now spent a solid three games talking shit about the Circle of Magi, so I'm not compelled to get to keep her around much.
Cole: I regret spending as little time with him as I did in my first play through, I couldn't figure out where he was in the base because I'm an idiot. Now that I'm seeing more of him on my second play through I'm really digging all of his dialogue in the world but I feel like they could be using him for more then they are.
Blackwall: They don't do enough with his mid game twist, he could have been really interesting but he isn't.
Dorian: I really like Dorian, on paper he seems really stock and still kinda is in game but everything about him just works really well. Talking to him about his homeland was some of my favorite dialogue in the game.
Iron Bull: He is really fun, not super deep, but fun. Wish they had done more with the Ben-Hassrath stuff but either way I enjoyed him.
Sera: I totally get why some people don't like her. She was really annoying to me when you first meet her but after that first scene I started to enjoy her quite a bit and the conversations she has with the other party members are great.
On my first play through I was a mage and my normal party was, Cassandra, Iron Bull and Sera. For the second play through I'm a two handed warrior and my party is, Cassandra, Cole and Dorian.